Common Skin Infestations in Children: A Clinical Overview for UK Primary Care Professionals

Skin infestations in children are frequently encountered in primary care and can lead to significant discomfort, itching, and secondary infections if left untreated. Early recognition is vital to prevent complications and reduce the transmission of these infestations in households, schools, and communities. This article will focus on three common infestations seen in children: head lice (Pediculus humanus capitis), scabies (Sarcoptes scabiei), and threadworms (Enterobius vermicularis). Each section outlines the clinical presentation, differential diagnosis, and evidence-based treatment options for primary care providers.

1. Head Lice (Pediculosis Capitis)

Clinical Presentation:

Head lice infestations are caused by Pediculus humanus capitis, obligate ectoparasites that live on the human scalp and feed on blood. These infestations are particularly common in school-aged children. The primary symptom is pruritus, often localised to the occipital and postauricular regions, due to an allergic reaction to louse saliva. Scratching can lead to secondary bacterial infections, typically presenting as impetigo with erythematous lesions and crusting. Lice are difficult to visualise directly, but their eggs (nits) can often be found firmly attached to the base of hair shafts.

Differential Diagnosis:

Seborrhoeic dermatitis: Characterised by greasy scaling and erythema on the scalp, it can sometimes mimic head lice but lacks the presence of lice or nits.

Tinea capitis: This fungal infection presents with scaling, pruritus, and alopecia, but unlike head lice, it does not feature visible nits or lice on the scalp.

Treatment:

The first-line pharmacological treatment for head lice is topical permethrin 1% or malathion 0.5% lotion, applied to dry hair for the recommended duration. A second application, 7-10 days later, is critical to eliminate newly hatched nymphs. Resistance to permethrin has been reported, and in cases of treatment failure, options such as dimeticone, isopropyl myristate, or benzyl alcohol may be considered. Manual removal using wet combing with a fine-toothed comb, conducted every 3-4 days over two weeks, is another effective method, especially when pharmacological treatments are contraindicated. Household contacts should be screened and treated if lice are detected, and decontamination of bedding, clothing, and hairbrushes is recommended to prevent reinfestation.

To further enhance your knowledge of common paediatric skin infestations and minor illnesses, consider enrolling in PDUK’s Paediatric Minor Illness Course. This course provides comprehensive training on assessing and managing common childhood conditions encountered in primary care, helping you to improve patient outcomes in your practice.

2. Scabies (Sarcoptes Scabiei)

Clinical Presentation:

Scabies is caused by the mite Sarcoptes scabiei, which burrows into the stratum corneum of the skin, leading to intense pruritus, particularly at night. The primary lesions are erythematous papules, vesicles, and burrows, with burrows appearing as thin, greyish, serpiginous lines, typically located between the fingers, on the wrists, elbows, and around the waistline. In children, scabies can also affect the palms, soles, scalp, and face—areas not commonly involved in adults. Severe itching and secondary bacterial infections, such as impetigo, can occur due to persistent scratching.

Differential Diagnosis:

Atopic dermatitis: This common paediatric condition also presents with pruritus and erythematous lesions, but scabies can usually be differentiated by the presence of burrows and nocturnal pruritus.

Papular urticaria: Hypersensitivity reactions to insect bites can cause pruritic papules but lack the classic burrows and the distribution pattern of scabies.

Treatment:

The gold standard treatment for scabies is permethrin 5% cream, which is applied from the neck down (including the scalp in infants and young children) and left on for 8-12 hours. A second application is required 7-10 days later to eradicate newly hatched mites. Oral ivermectin, given as a single dose of 200 µg/kg and repeated after one week, is an alternative for older children, especially in cases of extensive infestation or if topical treatments fail. All close contacts, including asymptomatic family members, should be treated simultaneously to prevent reinfestation. Bedding and clothing should be washed at 60°C or sealed in plastic bags for at least 72 hours to eliminate mites.

For further training on recognising and managing dermatological conditions in children of diverse ethnicities, you can explore PDUK’s Diverse Dermatology: Identifying and Treating Acute Skin Conditions in Children and Young People. This course offers in-depth insights into the nuances of dermatological presentations across different skin types, equipping healthcare professionals with the skills to provide accurate diagnoses and tailored treatments.

3. Threadworms (Enterobiasis)

Clinical Presentation:

Threadworms (or pinworms), caused by Enterobius vermicularis, are a common intestinal helminth infection in children. The key symptom is perianal pruritus, which is typically worse at night when female worms migrate to the perianal region to lay eggs. Severe scratching can lead to excoriation and secondary bacterial infection. In some cases, abdominal pain, nausea, irritability, and sleep disturbances may also occur. Visualisation of the worms around the anus or on the child’s stool may confirm the diagnosis.

Differential Diagnosis:

Anal fissures: While perianal pruritus can occur with threadworms, fissures often cause pain and bleeding with defecation, distinguishing them from enterobiasis.

Perianal dermatitis: Dermatitis due to irritants or allergens can mimic threadworm-related pruritus but lacks the nocturnal symptom exacerbation and evidence of worms.

Treatment:

The treatment of choice for threadworms is oral mebendazole (100 mg), which is administered as a single dose and repeated after two weeks to target newly hatched larvae. Pyrantel pamoate is an alternative in cases of mebendazole intolerance. Good hygiene practices, such as thorough handwashing, regular cleaning of the perianal region, and frequent laundering of bed linens and clothes, are essential in preventing reinfection. All household members should be treated simultaneously, regardless of symptomatology, to avoid reinfestation.

Conclusion

Understanding the clinical presentation and management of common skin infestations in children is crucial for primary care professionals. Head lice, scabies, and threadworms present with distinct patterns of pruritus and skin lesions, making accurate diagnosis and timely treatment imperative. Alongside pharmacological interventions, educating families on hygiene and environmental decontamination is key to reducing reinfestation and preventing community spread. Early intervention, patient education, and proper follow-up are essential to managing these common paediatric infestations effectively in the primary care setting.

For professionals looking to expand their knowledge and skills in managing these conditions, consider enrolling in PDUK’s Paediatric Minor Illness Course and Diverse Dermatology Course, designed specifically for healthcare providers working with children.

References:

Andrews RM, McCarthy JS, Carapetis JR. Skin Disorders in Children: A Review. Pediatrics. 2022; 149(3)

Heukelbach J, Feldmeier H. Scabies. Lancet. 2023; 402(10397):1247-1256.